1. Field of the Invention
The present invention relates to a shake correction control circuit provided with a function for correcting vibration such as one caused by camera shake, and an image pickup apparatus that includes said shake correction control circuit.
2. Description of the Related Art
Digital still cameras and digital movie cameras (hereinafter generically referred to as digital cameras) have been widely used by general users. Various methods for correcting camera shake are proposed for users who are not familiar with how to handle the cameras properly and therefore are likely to encounter camera shake when taking pictures. Among those digital cameras available, there is one, mounted on a portable telephone, which serves as one of functions in the portable telephone and a certain type of them are so designed that the camera is held by one hand only. In such devices operated by a thumb in one hand, the shake is more likely to occur as compared with commonly used cameras held by two hands to take pictures.
In order to correct such a shake, an optical shake correction and an electronic shake correction are in practical use, for instance. The optical shake correction is a method for correcting the optical axis by a vibration detecting element for detecting the vibration of a camera and a driver element that moves the position of a lens in such a direction as to cancel out the displacement caused by the vibration. The electronic shake correction is a method where the movement between adjacent image frames in moving images is identified by detecting the feature points or the like of the images and a cut-out position in an image pickup region is varied in such a manner as to cancel out the movement.
An advantageous aspect of the optical shake correction is that the correction can be done by using a single frame image only. On the other hand, a plurality of frames are required for the detection of any movement in the electronic shake correction and therefore the shake cannot be corrected if the shake occurs within a single frame. In the optical shake correction, a mechanical drive mechanism is required for the correction of the lens position which is problematic in terms of the electric power consumed.
Compared with the optical shake correction, the electronic shake correction has an advantageous aspect of being less power consuming. However, the correction is dependent on the frame rate. If the frame rate is low, highly accurate correction will be difficult to achieve in the electronic shake correction.